FRISCO (CBSDFW.COM) – The Exide plant and lead smelter in Frisco may be gone, but concerns about its pollution remain.

Newly-released city documents show problems extend beyond the shuttered plant and into recently-purchased land where Frisco is planning a large park, called Grand Park.

But a couple of field tests revealed potential danger. Such as, Meghan Green suggests,”A child picking up a chip, different types of batteries.”

Green is a Frisco mother and occasional spokeswoman for Frisco Unleaded, a community group wanting more done to clean up the controversial Exide battery plant. “We have to combat it at the source of the problem,” she said.

The proposed park sits on Stewart Creek, which runs through the recently-closed plant.

The city and environmentalists feared runoff could contaminate areas downstream, so Frisco authorized two tests. One showed unacceptable levels of lead, cadmium, and arsenic in sediment. A second walking test turned up pieces of batteries apparently washed downstream.

Mack Borchardt, a special assistant to the Frisco City Manager, said city officials were not surprised. “Our approach has been to identify what’s there, and in fact there’s been some identified, and then remediating it.”

The city eventually hopes to build a giant park with ponds, a boathouse, and other amenities. It said environmental tests are a necessary part of its due diligence. But environmentalists like Green claim the results were hidden.

“And that wasn’t public knowledge. We had to find that out through the open records request.”